Buttonhole-sewing machine



Dec. 10, 192-9.

E. B. ALLEN wr'rouxunn sswmer mcnm:

Filed Dec. 24. L827 4 Sheets-Sheet 1 INVENTOR 6% ATTORNEY WITNE ES Dec. 10, 192-9. E. B. ALLEN BUTTONHOLE SEWING MACHINE 4 Sheets-Sheet 2 Filed Doc. 24. 1927 v ATTORNEY WITNESSES E. B. ALLEN BUTTONH'OLE SEWING Indium Fi1ed-De6 .24. i927 Dan. 10, 1929.

4 Sheets- Sheet &

INVENTOR ATTORNEY Dec. 10, 1929; 'E. B.- ALLEN BUTTONHOLE SEWING MACHINE Filed-Dec. 2.4. 1927 4 shaets -syhpet 4 INVENTOR m g 7- TTORNEY V I wlmEsggs Patented Dec. 10, 1929 UNITED STATES PAT-ENT OFFICE EDWARD .B. ALLEN, or NEWTOWN, CONNECTICUT, ASSIGNOR TO THE SINGER MANU- "racronme COMPANY, or ELIZABETH, new JERSEY, A conrone'rron on NEW JERSEY BUTTONHOLE-SEWING MACHINE Application filed December 24, 1927. Serial No. 242,381.

This invention relates to buttonhole sewingmachines and has for an object to provide a machine which will make buttonholes having the appearance of hand-made buttonholes, while retaining the desirable wearing qualities of machine-made buttonholes.

, The equipment of a custom tailor for making garments is usually'limited to plain sewing machines for theiseaming operations, as the limited number of buttonhole's to be made would not ordinarily Warrant the expense incident to. the installationbf a buttonhole sewing machine. Hence, through necessity, the buttonholes of custom tailored clothing have been made by hand.

'- Many manufacturers of ready-to-wear clothing, desiring to have their garments simulate custom-made clothing, have adopted the use of hand-made buttonholes, despite the admitted fact that hand-made buttonholes do not have the regular and even appearance of, or wear as well as, machine-made buttonholes.

One of the characteristics of hand-made buttonholes is the coarseness of the stitching, as it is not customary to place as many stitches in a hand-made buttonhole as are placed in a machine-made buttonhole. Ordinarily, in sewing a buttonhole, the fewer punctures that are made by the needle, the stronger will be the buttonhole and the longer it will wear. With machine-made buttonholes, however, such as have hereto: fore been known, it has required more punctures of the needle to lay the threads closely enough along the cut edge of the material to properly cover such edge.

The present machine has been designed to sew a buttonhole having fewer stitches than have heretofore been considered feasible in a machine-made buttonhole Without sacrifice of a well covered cut edge. It has also been designed to lay the thread-lengths between the depth-stitch punctures and the slit on the back or reverse face of the material in spaced relation and normal to the buttonhole-slit in simulation of hand-made buttonholing.

In buttonhole machines, as heretofore constructed, the feeding mechanisms is designed to feed the'work after each descent of a present direction opposite to the direction of feed,

as the needle is rising from its slit-stitch descent. The effect ofthis movement of the needle is to carry the needle-threadforwardly so that it will be drawn over the corner of the cut edge at a point even with theensuing depth-stitch, to insure that the needle-thread extending from the slit to the depth-stitch will lie normal to the buttonholeslit. Thus, the needle-thread lengths appearing on the back face of the material will tend to lie at parallel formation, instead of in zigzag formation, as heretofore. This movement of the needle also has a wiping effect upon any projecting cut-thread ends of the body-material, bending them forwardly or parallel to the slit just prior to the. laying of the needle-thread over such thread-ends, whereby the latter are smoothly bound and concealed. I

.Buttonholes are usually sewnthrough two plies of material and one ply of a light colored interlining. If the cut edge of this interlining is not well covered by the threads of the buttonhole stitches, inking must be resorted to, to hide the interlining. In buttonholes, such as made by machines heretofore known, the needle-thread lengths passing through the slit, across the plane of the interlining are grouped in parallel pairs and do not effectively cover the interlining,

unless thestitches are rather closely spaced.

According to In buttonholes made in accordance with'the improvement, the needle-thread lengths passing through the slit are separated or spread into a zigzag or saw-tooth course and are much more effective 1n covering the mterhnmg. In fact, substantially the same slit-covering effect is had with half the number of needle-penetrations required of prior Figs. 11 and 12 are front and reverse views of the needle-mechanism. Fig. 13 is an elevation of the side of the needle mechanism oppositeto that shown in Fig. '7. Fig. 14 is a section on the line 1414, Fig. 11. Figs. 15 and 16 are detailed perspective views of elements of the needle mechanism. Figs. 17

rotary turret 7.. 1

present improvement.

looper-thread loops.

and 18 are plan and sectional views of the buttonhole as made in accordance with the prior art, butwith coarsely spaced-stitches. Figs. 19 and20 are similar Views of a buttonholeas made in accordance with the Fig. 21 is a plan viewjo'f the overseam on the opposite side of the. buttonhole from that shown in Fig. 19, and' Fig. 22 is a perspective view of the buttonhole overseam, showing the arrangementand concatenation of the needleand -The invention is preferably embodied in an automatic buttonhole sewing nachinehaving the constructive features disclosed in the patent to Allen No. 1,548,815, of August ll, 1925. Such a machine is constructed, with a hollow rectangular bed 1' from which rises the standard 2 of the bracket-arm 3 terminating in the head 4 carrying the upper-thread mechanism in- 'cluding the eye-pointed needle 5; the underthreadv mechanism 6 being carried by the The work is held in the usual travelling work-clamp 8 which initially clamps the work in a position rearwardly of stitching position for action of the buttonhole cutting mechanism 9. The work-clamp derives its travelling movements, as usual,'from the feed-wheel 10 which, after the buttonhole is cut, israpidly driven by thegear-connection 11..with the cross-shaft 12 having the usual clutch-and-gear connection 13 with the constantly running rapid-feed drivingshaft 14. This-rapid-drive of the feedwheel quickly shifts the work-clamp with the cut buttonhole to stitching position. whereupon the rapid-feed drive is interrupted and the stitching-feed drive rendered effective. In the present machine, the

stit'ching-feed drive comprises the usual stitch-gear connections 15 with the shaft 16 carrying the star-wheel 17 which heretofore was driven by a pair of diametrically op-- posed pins in the lower end of the vertical sewing-shaft, asdisclosed in the Allen Patent No. 15,324, reissuedApril 4, 1922. As the vertical sewing-shaft commonly has a one-to-two speed-multiplying 'gear-connection to the needle-bar driving-shaft, these two pins gave the feed-wheel a feeding impulse for each reciprocation of the needle,

thus feeding the work after both the slit'- and depth-stitches.

According to the present improvement,

the vertical sewing shaft 18 carries but one feed-driving pin 19 which gives to the star? wheel 17 and the feed-wheel 10 but one feeding impulse for each two reciprocations'of the needle 5. The pin 19 istimed to give 3 the feedin impulse as the needle is rising from its s it-stitch descent; the feedbeing completed before the needle-point strikes the material on its depth-stitch thrust.

To hold the star-wheel 17 locked while the pin'19 is out of engagement therewith, there is provided on the'main sewing shaft 20, a collar 21 formed with a locking rib 22 entering one of the series of slots 23 in the under face of thestar-wheel 17.

The main sewing shaft 20 has the .usual one-to-one gear connection 24 with the verusual one-to-two speed-multiplying gear tical sewing shaft 18 which, in turn, has the 7 connection 25 with the needle-bar actuating 1 shaft 26. The shafts 18, 20, star-wheel 17,

and stitch-gears 15 are carried by the usual bearing bracket 27 which is'secured within the hollow bed 1.

The stitch-forming mechanism including the needle-bar mechanism of the machine is in general, constructed substantially 1n .ac-'

cordance with the disclosure of the patent to Allen No. 1,161,277, of November 23,

1915, and the patent to Allen, et al., No.

1,372,473, of March 22,1921, but with the difference that the present mechanism includes means for additionally'vibrating the needle longitudinally of the buttonhole slit,

in a direction opposite to the direction of,

feed ofthe work, as the needle is rising from its slit-stitch descent.

The usual rotary and reciprocatory needle bar 28 is journaled inthe usual rotary bushing 29 and carries at its lower end the yoke 30, the r vertical members of which are connected by the bearing-pin 31 on which is slidably mounted the carrier 32 for the needle 5. The carrier 32 has two spaced, parallel, upstandlng bearing plates 33, 34, of which the plate 33 is held against the horizontal member of the yoke 30 by the spring 35.

When the needle-carrier 32 is in slit-stitch position on the pin 31, the plate 34 is spaced from the yoke 30, as shown in full-lines in F g. 14, so that the carrier 32 may partake of a limited turning or tilting movement on the pin 31, as shown in dotted lines, Fig. 8. When the needle-carrier 32 occupies depthstitch position on the pin 31, the plate 34, (in dotted line position, Fig. 14) engages the lug 30 on the yoke 30 and is thus held rigidly in a vertical position.

For sliding the needle-carrier 32 on the bearing-pin 31, the usual mechanism, such as disclosed in said Patent-s No. 1,161,277 and No. 1,372,473, is provided. This mechanism comprises a lever 36, which is fulcruined at 37 on the cross-bar 38 connecting the vertical arms of the yoke 30. The lever 36' has mounted thereon for adjustment lengthwise of the slot 39, a pin 40 which enters a vertical slot 41 in the plate 34 of the needle-carrier 32. The lever 36carries at its upper end a pin 42 which alternately plays in the spaced vertical guideways 43, 44 in the block 47 fixed by screws 48 to the block 49 which is integral with the rotary needle-bar bearing-sleeve 29. The pin 42 is shifted from one to the other of the guideways 43, 44, by means of the usual forked bell-crank switch-lever 5O fulcrumed at 51 on the block 47 and having a pin 52 entering the circular groove 53 in the ring 54 fixed to the lower end of the vertically reciprocating slide-rod 55..

The slide-rod 55 is actuated by a link-connection 56 with a bell-crank lever 57 which is connected by a link 58 to a vibrating lever (not shown) within the standard 2. It will be understood that as the needle-bar 28 nears the end of its up-stroke, the pin 42 leaves the upper end of one of the guideways 43, 44, and enters the forked end of the bell-crank lever 50 which is thereupon rocked by vertical movement of the ring 54 to switch the pin 42 over into position to enter the other guideway when the needle descends. This rocking movement of the lever 36 slides the needlecarrier 32 on the pin 31 and thus vibrates the needle, as usual, transversely of the buttonhole slit, to alternately make the usual depthand slit-stitches.

According to the present improvement, the block 45 in which the guideways 43, 44 are formed, has mounted thereon a pair of links carrying the vertically disposed cam-plate 60. A spring 61 yieldingly urges the camplate 60 upwardly with the link 59 in engagement with the stop-pin 62. The plate 34 of the needle-carrier 32 is formed with a tooth 63 which, when the needle-carrier 32 is rising in slit-stitch position, is in position to engage the cam-plate 60, as shown in dotted lines, Fig. 8, and tilt the needle-carrier, thus shifting the needle longitudinally of the button hole slit, in a direction opposite to the direction of feed. This motion of the needle in the buttonhole slit wipes or bends over any projecting cut thread-ends 01": the body-material preparatory to laying the needle-thread over such cut thread-ends to smoothly cover the latter. it Further, the needle-thread is carried forwardly and bent over thecut edge of the material at a point even with the ensuing depth-stitch, insuringthat the needle-thread the needle to, and its descent in, slit-stitch position lays the needle-thread in a vertical plane normal to the buttonhole slit, both on.

the 'face of the material and down through the slit. The vibration of the needle longitudinally of thebuttonhole slit, as the needle rises from its slit-stitch descent, spaces the ascending needle-thread a, Fig. 20, from and lays it at an angle to the previous descending needlethread I); such spacing andangular arrangement serving to more thoroughly cover the cut threads of the body-material, and particularly, of the interlining c, which is usually of a contrasting color and must be inked if not well covered. 4 1 i v When the needle-carrier 32 is shifted to its depth-stitch position, shown ind otted lines, Fig. 14, the tooth 63 is moved to one side of the cam-plate 60 and does not engage the latter. When the needle-carrier descends in slit-stitch position, the tooth 63 engages and idlyidepresses the cam-plate 60 without being tilted on the bearing pin 31.

The buttonhole made by the present machine is described and claimed in my co-pending application Serial No. 242,382, filed here-1' with. It comprises the body-material which 65. The needle-thread is formed alternately into depth-stitch loops 66 and slit-stitch loops 67 which pass from one to the other face of the body-material. One limb 68 of each slit-stitch loop lies in a vertical plane normal to the buttonhole-slit and the other limb 69 of such loop extends at an angle, cl, to the;

limb 68 between the planes of the faces of the material; the limb 69 being drawn over the cut edge of the slit at a point 70 even with the ensuing depth-stitch loop 66.. Thus, thepresent buttonhole is characterized by the tendency of the needle-thread lengths on bothfaces of the material to assume parallel relationship normal to the buttonhole slit, giving to the buttonhole the characteristic appearance 01 a hand-made buttonhole. The

feed of the work, and the lateral vibration of includes the two main-plies 64 and the interlining a, in which is cut-the buttonhole-slit l. A buttonhole sewing machine having,

in combination, buttonhole'cutting mechanism, stitch-forming mechanism including a reciprocating and laterally vibrating needle making a lateral vibrationafter eachreciprocation, a work-clamp, and means for relatively feeding the stitch-forming mechanism and work-clamp only after each two reciprocations of the needle, the stitch-forming mechanism and Work-clamp being held rela- ,tively stationary during the interval between the two reciprocations of the needle preceding each feeding movement. a V

2. A buttonhole sewing machine having,

in combination, stitch-forming mechanism including a reciprocating and laterally vibrating needle alternately making slitand V depth-stitches, a work-clamp, and means for relatively, feeding the stitch-forming mechanism and work-clamp only after each slitstitch descent of the needle, the stitch-forming mechanism and work-clamp being'held relatively stationary during the interval between the making of a depth-stitch and the following slitstitch. v

3. In a buttonhole sewing machine, in combination, over-edge stitch-forming mechanism including a reciprocating and laterally vibratlng needle alternately making depthand slit-stitches, a work-clamp, means for relatively feeding'the stitch-forming mechanism and Work-clamp only after each slit-stitch descent of the needle, the stitchforming mechanism and work-clamp" being held relatively stationary during the interval vbetween the making of a depth-stitch and the following slit-stitch, and means for moving the needle-thread longitudinally of the buttonhole slit in a direction opposite to the di- I rection of feed.

.4. In a buttonhole sewing machine, in combination, over-edge stitch-forming mechanism including a reciprocating and laterally vibrating needle alternately making the depthand slit-stitches, a work-clamp, means .for relatively feeding the stitch-forming mechanism and Work-clamp only after each slit-stitch descent, of the needle, the. stitchforming mechanism and work-clamp being held relatively stationary during the interval betweenthe making of a depth-stitch and the v following slit-stitch, and means for moving the needle in a direction opposite to the direction of feed during its slit-stitch reciprocation. 7

In testimony whereof, I have signed my name to this specification.

, EDWARD B. ALLEN. 

